PSTD and Laughing Gas

I had some emergency oral surgery yesterday, with the use of nitroux oxide (NO). I'm also currently in therapy for PSTD for being abused as a child. One of my coping skills for many many years has been disconnecting.
Well, the NO was the ultimate disconnection for me. I was pushing the its trying to disconnect from my body, I wanted to not come back even if it meant death. I was feeling so depressed.
When the NO was turned off, I was so sad and disappointed I was still alive and I had a hard time becoming present again. I would be okay for a couple minutes then feel like I'm going to pass out. For an hour I had to remain at the oral surgeons - my mind just didn't want to reconnect.
Eventually after they called my daughter to drive me home, I started to refocus more on connecting and started to get better. I didn't want to tell anyone what was really happening to me. Now today, I'm much better, not as depressed as I was on the NO, present, etc. But that scared me, I didn't expect that I could feel so much like dying (actually I felt like I was and was happy about it). I'll talk to my therapist about this next week but wanted to just see if anyone else had this experience. I know I don't want NO anymore...

Nitrous oxide is a Dissociative drug when used as an inhalant. A dissociative is a drug which reduces signals to the conscious mind from other parts of the brain usually in regard to the physical senses. Such a state of sensory deprivation and dissociation can facilitate self exploration, hallucinations, and dreamlike states of mind which may resemble some psychedelic mindstates.

It also produces mild euphoria, a slight aphrodisiac effect, and a sense of general well-being.

Its not uncommon to experience a "down" or disconected feeling after comming off of Nitrous oxide.